Data integrity and acceleration in compressed storage environments in combination with software defined native RAID

ABSTRACT

A mechanism is provided in a data processing system for data integrity and acceleration in compressed storage environments in combination with software defined native redundant array of independent disks (RAID). The mechanism receives a data portion to write to storage and divides the data portion into a plurality of chunks. The mechanism performs real-time compression on a given chunk within the plurality of chunks and determines a compression rate for the given chunk. The mechanism determines a RAID level for the given chunk based on a value of the compression rate and stores the given chunk based on the determined RAID level.

BACKGROUND

The present application relates generally to an improved data processingapparatus and method and more specifically to mechanisms for data,integrity and acceleration in compressed storage environments incombination with software defined native RAID.

RAID (redundant array of independent disks) is a data storagevirtualization technology that combines multiple disk drive componentsinto a single logical unit for the purposes of data redundancy orperformance improvement. RAID systems distribute data across the drivesin one of several ways, referred to as RAID levels, depending on thespecific level of redundancy and performance required.

A number of standard schemes have evolved. These are called levels.Originally, there were five RAID levels, but many variations haveevolved—notably several nested levels and many non-standard levels. RAIDlevels and their associated data formats are standardized by the StorageNetworking Industry Association (SNIA) in the Common RAID Disk DriveFormat (DDF) standard:

RAID 0 consists of striping, without mirroring or parity. The capacityof a RAID 0 volume is the sum of the capacities of the disks in the set,the same as with a spanned volume. There is no added redundancy forhandling disk failures, just as with a spanned volume. Thus, failure ofone disk causes the loss of the entire RAID 0 volume, with reducedpossibilities of data recovery when compared to a broken spanned volume.Striping distributes the contents of files roughly equally among alldisks in the set, which makes concurrent read or write operations on themultiple disks almost inevitable and results in performanceimprovements. The concurrent operations make the throughput of most readand write operations equal to the throughput of one disk multiplied bythe number of disks. Increased throughput is the big benefit of RAID 0versus spanned volume.

RAID 1 consists of data mirroring, without parity or striping. Data iswritten identically to two or more drives, thereby producing a “mirroredset” of drives. Thus, any read request can be serviced by any drive inthe set. If a request is broadcast to every drive in the set, it can beserviced by the drive that accesses the data first (depending on seektime and rotational latency), improving performance. Sustained readthroughput, if the controller or software is optimized for it,approaches the sum of throughputs of every drive in the set, just as forRAID 0. Actual read throughput of most RAID 1 implementations is slowerthan the fastest drive. Write throughput is always slower because everydrive must be updated, and the slowest drive limits the writeperformance. The array continues to operate as long as at least onedrive is functioning.

RAID 5 consists of block-level striping with distributed parity. RAID 5requires that all drives but one be present to operate. Upon failure ofa single drive, subsequent reads can be calculated from the distributedparity such that no data, are lost. RAID 5 requires at least threedisks.

RAID 6 consists of block-level striping with double distributed parity.Double parity provides fault tolerance up to two failed drives. Thismakes larger RAID groups more practical, especially forhigh-availability systems, as large-capacity drives take longer torestore. RAID 6 requires a minimum of four disks. As with RAID 5, asingle drive failure results in reduced performance of the entire arrayuntil the failed drive has been replaced. With a RAID 6 array, usingdrives from multiple sources and manufacturers, it is possible tomitigate most of the problems associated with RAID 5. The larger thedrive capacities and the larger the array size, the more important itbecomes to choose RAID 6 instead of RAID 5.

RAID 1+0, also referred to as RAID 10, creates a striped set from aseries of mirrored drives. The array can sustain multiple drive lossesso long as no mirror loses all its drives.

Software RAID implementations are now provided by many operatingsystems. Software RAID can be implemented as a layer that abstractsmultiple devices, thereby providing a single virtual device, a moregeneric logical volume manager, a component of the file system, or alayer that sits above any file system and provides parity protection touser data. Some advanced file systems are designed to organize dataacross multiple storage devices directly without needing the help of athird-party logical volume manager. The General Parallel File System(GPFS), initially developed by IBM for media streaming and scalableanalytics, supports de-clustered RAID protection schemes up to n+3. Aparticularity is the dynamic rebuilding priority which runs with lowimpact in the background until a data chunk hits n+0 redundancy, inwhich case this chunk is quickly rebuilt to at least n+1. On top, GPFSsupports metro-distance RAID 1.

Data optimization for primary storage is a key initiative for datacenter managers today. Data center managers are looking for ways toimprove storage utilization as well as trying to reduce one of thelargest line items in the Information Technology (IT) budget: the costto maintain a storage environment. Optimizing data on the primarystorage tier also has a ripple effect, as cost savings then permeatethroughout the data lifecycle. While deduplication captures most of theheadlines, it is not the sole option to be considered. An alternative oreven potential compliment to deduplication is real-time compression.

Real-time compression is an in-line storage optimization technologyoften implemented on an appliance that is commonly deployed into storageenvironments. Logically the appliance sits in front of the storage,processing all data coming into and out of the storage through thereal-time compression technology.

SUMMARY

In one illustrative embodiment, a method, in a data processing system,is provided for data integrity and acceleration in compressed storageenvironments in combination with software defined native redundant arrayof independent disks (RAID). The method comprises receiving a dataportion to write to storage and dividing the data portion into aplurality of chunks. The method further comprises performing real-timecompression on a given chunk within the plurality of chunks anddetermining a compression rate for the given chunk. The method furthercomprises determining a RAID level for the given chunk based on a valueof the compression rate and storing the given chunk based on thedetermined RAID level.

In other illustrative embodiments, a computer program product comprisinga computer useable or readable medium having a computer readable programis provided. The computer readable program, when executed on a computingdevice, causes the computing device to perform various ones of, andcombinations of, the operations outlined above with regard to the methodillustrative embodiment.

In yet another illustrative embodiment, a system/apparatus is provided.The system/apparatus may comprise one or more processors and a memorycoupled to the one or more processors. The memory may compriseinstructions which, when executed by the one or more processors, causethe one or more processors to perform various ones of, and combinationsof, the operations outlined above with regard to the method illustrativeembodiment.

These and other features and advantages of the present invention will bedescribed in, or will become apparent to those of ordinary skill in theart in view of, the following detailed description of the exampleembodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, as well as a preferred mode of use and further objectivesand advantages thereof, will best be understood by reference to thefollowing detailed description of illustrative embodiments when read inconjunction with the accompanying drawings, wherein:

FIG. 1 depicts a cloud computing node according to an illustrativeembodiment;

FIG. 2 depicts a cloud computing environment according an illustrativeembodiment;

FIG. 3 depicts abstraction model layers according to an illustrativeembodiment;

FIG. 4 depicts storage with real-time compression in accordance with anillustrative embodiment;

FIG. 5 is a block diagram of a software defined. RAID data handlingmodule in accordance with an illustrative embodiment;

FIG. 6 shows an example mapping of predefined RAID levels forcompression rates in accordance with an illustrative embodiment;

FIG. 7 shows an example mapping of predefined performance levels forcompression rates in accordance with an illustrative embodiment; and

FIG. 8 is a flowchart illustrating operation of a data handling modulefor data integrity and acceleration in compressed storage environmentswith software defined native RAID in accordance with an illustrativeembodiment.

DETAILED DESCRIPTION

The illustrative embodiments provide mechanisms for data integrity andacceleration in compressed storage environments in combination withsoftware defined native RAID. The illustrative embodiments providemechanisms for dynamic creation and data placement on different. RAIDprotection levels. In one embodiment, the data center manager maydetermine that data with higher compression rate are more importantbecause they are more susceptible to data corruption, while data withlower compression rate are less susceptible to data corruption and,thus, are less important. The mechanisms then place data with highercompression rate on higher RAID protection levels and place data withlower compression rate on lower RAID protection levels.

In an alternative embodiment, the data center manager may determine thatdata with higher compression rate are less important because theycontain less information, while data, with a lower compression rate aremore important because they contain more information. In the alternativeembodiment, the mechanisms reverse the RAID protection levels, placingdata with higher compression rate on lower RAID protection levels andplacing data with lower compression rate on lower RAID protectionlevels.

In other embodiments, mechanisms perform dynamic data placement betweendifferent performance pools. In one embodiment, the data center managermay determine that data with higher compression rate experience greaterimpact of the real-time compression engine and that data with lowercompression rate experience less impact of the real-time compressionengine. The mechanisms then place data with higher compression rate onhigher performance storage pools and place data with lower compressionrate on lower performance storage pools to compensate for the negativeperformance impact of the real-time compression engine.

In an alternative embodiment, the data center manager may determine thatdata with higher compression rate are stored at a faster rate due to thehigher amount of information per data unit and that data with lowercompression rate are stored more slowly. The mechanisms then place datawith higher compression rate on lower performance storage pools andplace data with lower compression rate on higher performance storagepools to compensate for the positive performance impact of the real-timecompression engine.

Before beginning the discussion of the various aspects of theillustrative embodiments, it should first be appreciated that throughoutthis description the term “mechanism” will be used to refer to elementsof the present invention that perform various operations, functions, andthe like. A “mechanism,” as the term is used herein, may be animplementation of the functions or aspects of the illustrativeembodiments in the form of an apparatus, a procedure, or a computerprogram product. In the case of a procedure, the procedure isimplemented by one or more devices, apparatus, computers, dataprocessing systems, or the like. In the case of a computer programproduct, the logic represented by computer code or instructions embodiedin or on the computer program product is executed by one or morehardware devices in order to implement the functionality or perform theoperations associated with the specific “mechanism.” Thus, themechanisms described herein may be implemented as specialized hardware,software executing on general purpose hardware, software instructionsstored on a medium such that the instructions are readily executable byspecialized or general purpose hardware, a procedure or method forexecuting the functions, or a combination of any of the above.

The present description and claims may make use of the terms “a,” “atleast one of,” and “one or more of” with regard to particular featuresand elements of the illustrative embodiments. It should be appreciatedthat these terms and phrases are intended to state that there is atleast one of the particular feature or element present in the particularillustrative embodiment, but that more than one can also be present.That is, these terms/phrases are not intended to limit the descriptionor claims to a single feature/element being present or require that aplurality of such features/elements be present. To the contrary, theseterms/phrases only require at least a single feature/element with thepossibility of a plurality of such features/elements being within thescope of the description and claims.

In addition, it should be appreciated that the following descriptionuses a plurality of various examples for various elements of theillustrative embodiments to further illustrate example implementationsof the illustrative embodiments and to aid in the understanding of themechanisms of the illustrative embodiments. These examples intended tobe non-limiting and are not exhaustive of the various possibilities forimplementing the mechanisms of the illustrative embodiments. It will beapparent to those of ordinary skill in the art in view of the presentdescription that there are many other alternative implementations forthese various elements that may be utilized in addition to, or inreplacement of, the examples provided herein without departing from thespirit and scope of the present invention.

It is understood in advance that although this disclosure includes adetailed description on cloud computing, implementation of the teachingsrecited herein are not limited to a cloud computing environment. Rather,embodiments of the present invention are capable of being implemented inconjunction with any other type of computing environment now known orlater developed.

Cloud computing is a model of service delivery for enabling convenient,on-demand network access to a shared pool of configurable computingresources (e.g. networks, network bandwidth, servers, processing,memory, storage, applications, virtual machines, and services) that canbe rapidly provisioned and released with minimal management effort orinteraction with a provider of the service. This cloud model may includeat least five characteristics, at least three service models, and atleast four deployment models.

Characteristics are as follows:

On-demand self-service: a cloud consumer can unilaterally provisioncomputing capabilities, such as server time and network storage, asneeded automatically without requiring human interaction with theservice's provider.

Broad network access: capabilities are available over a network andaccessed through standard mechanisms that promote use by heterogeneousthin or thick client platforms (e.g., mobile phones, laptops, and PDAs).

Resource pooling: the provider's computing resources are pooled to servemultiple consumers using a multi-tenant model, with different physicaland virtual resources dynamically assigned and reassigned according todemand. There is a sense of location independence in that the consumergenerally has no control or knowledge over the exact location of theprovided resources but may be able to specify location at a higher levelof abstraction (e.g., country, state, or datacenter).

Rapid elasticity: capabilities can be rapidly and elasticallyprovisioned, in some cases automatically, to quickly scale out andrapidly released to quickly scale in. To the consumer, the capabilitiesavailable for provisioning often appear to be unlimited and can bepurchased in any quantity at any time.

Measured service: cloud systems automatically control and optimizeresource use by leveraging a metering capability at some level ofabstraction appropriate to the type of service (e.g., storage,processing, bandwidth, and active user accounts). Resource usage can bemonitored, controlled, and reported providing transparency for both theprovider and consumer of the utilized service.

Service Models are as follows:

Software as a Service (SaaS): the capability provided to the consumer isto use the provider's applications running on a cloud infrastructure.The applications are accessible from various client devices through athin client interface such as a web browser (e.g., web-based email). Theconsumer does not manage or control the underlying cloud infrastructureincluding network, servers, operating systems, storage, or evenindividual application capabilities, with the possible exception oflimited user-specific application configuration settings.

Platform as a Service (PaaS): the capability provided to the consumer isto deploy onto the cloud infrastructure consumer-created or acquiredapplications created using programming languages and tools supported bythe provider. The consumer does not manage or control the underlyingcloud infrastructure including networks, servers, operating systems, orstorage, but has control over the deployed applications and possiblyapplication hosting environment configurations.

Infrastructure as a Service (IaaS): the capability provided to theconsumer is to provision processing, storage, networks, and otherfundamental computing resources where the consumer is able to deploy andrun arbitrary software, which can include operating systems andapplications. The consumer does not manage or control the underlyingcloud infrastructure but has control over operating systems, storage,deployed applications, and possibly limited control of select networkingcomponents (e.g., host firewalls).

Deployment Models are as follows:

Private cloud: the cloud infrastructure is operated solely for anorganization. It may be managed by the organization or a third party andmay exist on-premises or off-premises.

Community cloud: the cloud infrastructure is shared by severalorganizations and supports a specific community that has shared concerns(e.g., mission, security requirements, policy, and complianceconsiderations). It may be managed by the organizations or a third partyand may exist on-premises or off-premises.

Public cloud: the cloud infrastructure is made available to the generalpublic or a large industry group and is owned by an organization sellingcloud services.

Hybrid cloud: the cloud infrastructure is a composition of two or moreclouds (private, community, or public) that remain unique entities butare bound together by standardized or proprietary technology thatenables data and application portability (e.g., cloud bursting for loadbalancing between clouds).

A cloud computing environment is service oriented with a focus onstatelessness, low coupling, modularity, and semantic interoperability.At the heart of cloud computing is an infrastructure comprising anetwork of interconnected nodes.

Referring now to FIG. 1, a schematic of an example of a cloud computingnode is shown. Cloud computing node 10 is only one example of a suitablecloud computing node and is not intended to suggest any limitation as tothe scope of use or functionality of embodiments of the inventiondescribed herein. Regardless, cloud computing node 10 is capable ofbeing implemented and/or performing any of the functionality set forthhereinabove.

In cloud computing node 10 there is a computer system/server 12, whichis operational with numerous other general purpose or special purposecomputing system environments or configurations. Examples of well-knowncomputing systems, environments, and/or configurations that may besuitable for use with computer system/server 12 include, but are notlimited to, personal computer systems, server computer systems, thinclients, thick clients, handheld or laptop devices, multiprocessorsystems, microprocessor-based systems, set top boxes, programmableconsumer electronics, network PCs, minicomputer systems, mainframecomputer systems, and distributed cloud computing environments thatinclude any of the above systems or devices, and the like.

Computer system/server 12 may be described in the general context ofcomputer system executable instructions, such as program modules, beingexecuted by a computer system. Generally, program modules may includeroutines, programs, objects, components, logic, data structures, and soon that perform particular tasks or implement particular abstract datatypes. Computer system/server 12 may be practiced in distributed cloudcomputing environments where tasks are performed by remote processingdevices that are linked through a communications network. In adistributed cloud computing environment, program modules may be locatedin both local and remote computer system storage media including memorystorage devices.

As shown in HG. 1, computer system/server 12 in cloud computing node 10is shown in the form of a general-purpose computing device. Thecomponents of computer system/server 12 may include, but are not limitedto, one or more processors or processing units 16, a system memory 28,and a bus 18 that couples various system components including systemmemory 28 to processor 16.

Bus 18 represents one or more of any of several types of bus structures,including a memory bus or memory controller, a peripheral bus, anaccelerated graphics port, and a processor or local bus using any of avariety of bus architectures. By way of example, and not limitation,such architectures include Industry Standard Architecture (ISA) bus,Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, VideoElectronics Standards Association (VESA) local bus, and PeripheralComponent Interconnects (PCI) bus.

Computer system/server 12 typically includes a variety of computersystem readable media. Such media may be any available media that isaccessible by computer system/server 12, and it includes both volatileand non-volatile media, removable and non-removable media.

System memory 28 can include computer system readable media in the formof volatile memory, such as random access memory (RAM) 30 and/or cachememory 32. Computer system server 12 may further include otherremovable/non-removable, volatile/non-volatile computer system storagemedia. By way of example only, storage system 34 can be provided forreading from and writing to a non-removable, non-volatile magnetic media(not shown and typically called a “hard drive”). Although not shown, amagnetic disk drive for reading from and writing to a removable,non-volatile magnetic disk (e.g., a “floppy disk”), and an optical diskdrive for reading from or writing to a removable, non-volatile opticaldisk such as a CD-ROM, DVD-ROM or other optical media can be provided.In such instances, each can be connected to bus 18 by one or more datamedia interfaces. As will be further depicted and described below,memory 28 may include at least one program product having a set (e.g.,at least one) of program modules that are configured to carry out thefunctions of embodiments of the invention.

Program/utility 40, having a set (at least one) of program modules 42,may be stored in memory 28 by way of example, and not limitation, aswell as an operating system, one or more application programs, otherprogram modules, and program data. Each of the operating system, one ormore application programs, other program modules, and program data orsome combination thereof, may include an implementation of a networkingenvironment. Program modules 42 generally carry out the functions and/ormethodologies of embodiments of the invention as described herein.

Computer system/server 12 may also communicate with one or more externaldevices 14 such as a keyboard, a pointing device, a display 24, etc.;one or more devices that enable a user to interact with computersystem/server 12; and/or any devices (e.g., network card, modem, etc.)that enable computer system/server 12 to communicate with one or moreother computing devices. Such communication can occur via Input/Output(I/O) interfaces 22. Still yet, computer system/server 12 cancommunicate with one or more networks such as a local area network(LAN), a general wide area network (WAN), and/or a public network (e.g.,the Internet) via network adapter 20. As depicted, network adapter 20communicates with the other components of computer system/server 12 viabus 18. It should be understood that although not shown, other hardwareand/or software components could be used in conjunction with computersystem/server 12. Examples, include, but are not limited to: microcode,device drivers, redundant processing units, external disk drive arrays,RAID systems, tape drives, and data archival storage systems, etc.

Referring now to FIG. 2, illustrative cloud computing environment 50 isdepicted. As shown, cloud computing environment 50 comprises one or morecloud computing nodes 10 with which local computing devices used bycloud consumers, such as, for example, personal digital assistant (PDA)or cellular telephone 54A, desktop computer 5413, laptop computer 54C,and/or automobile computer system 54N may communicate. Nodes 10 maycommunicate with one another. They may be grouped (not shown) physicallyor virtually, in one or more networks, such as Private, Community,Public, or Hybrid clouds as described hereinabove, or a combinationthereof. This allows cloud computing environment 50 to offerinfrastructure, platforms and/or software as services for which a cloudconsumer does not need to maintain resources on a local computingdevice. It is understood that the types of computing devices 54A-N shownin FIG. 2 are intended to be illustrative only and that computing nodes10 and cloud computing environment 50 can communicate with any type ofcomputerized device over any type of network and/or network addressableconnection (e.g., using a web browser).

Referring now to FIG. 3, a set of functional abstraction layers providedby cloud computing environment 50 (FIG. 2) is shown. It should beunderstood in advance that the components, layers, and functions shownin FIG. 3 are intended to be illustrative only and embodiments of theinvention are not limited thereto. As depicted, the following layers andcorresponding functions are provided:

Hardware and software layer 60 includes hardware and softwarecomponents. Examples of hardware components include mainframes, in oneexample IBM® zSeries® systems; RISC (Reduced Instruction Set Computer)architecture based servers, in one example IBM pSeries® systems; IBMxSeries® systems; IBM BladeCenter® systems; storage devices; networksand networking components. Examples of software components includenetwork application server software, in one example IBM WebSphere®application server software; and database software, in one example IBMDB2® database software. (IBM, zSeries, pSeries, xSeries, BladeCenter,WebSphere, and DB2 are trademarks of International Business MachinesCorporation registered in many jurisdictions worldwide).

Virtualization layer 62 provides an abstraction layer from which thefollowing examples of virtual entities may be provided: virtual servers;virtual storage; virtual networks, including virtual private networks;virtual applications and operating systems; and virtual clients.

In one example, management layer 64 may provide the functions describedbelow. Resource provisioning provides dynamic procurement of computingresources and other resources that are utilized to perform tasks withinthe cloud computing environment. Metering and Pricing provide costtracking as resources are utilized within the cloud computingenvironment, and billing or invoicing for consumption of theseresources. In one example, these resources may comprise applicationsoftware licenses. Security provides identity verification for cloudconsumers and tasks, as well as protection for data and other resources.User portal provides access to the cloud computing environment forconsumers and system administrators. Service level management providescloud computing resource allocation and management such that requiredservice levels are met. Service Level Agreement (SLA) planning andfulfillment provide pre-arrangement for, and procurement of, cloudcomputing resources for which a future requirement is anticipated inaccordance with an SLA.

Workloads layer 66 provides examples of functionality for which thecloud computing environment may be utilized. Examples of workloads andfunctions which may be provided from this layer include: mapping andnavigation; software development and lifecycle management; virtualclassroom education delivery; and data analytics processing; transactionprocessing.

FIG. 4 depicts storage with real-time compression in accordance with anillustrative embodiment. The amount of digitally stored information isdramatically increasing. Recent studies estimate that this growth willcontinue by a factor of approximately 40 within the next ten years. Inorder to mitigate this dramatic growth, one may use real-timecompression methods to eliminate or reduce the amount of duplicateddata.

As shown in FIG. 4, real-time compression engine 410 receives datachunks to be stored. A data chunk may be a file, a block, multipleblocks, etc. The data chunks may be a fixed or variable size. Real-timecompression engine 410 performs compression on the data chunks andpasses the compressed data chunks to data handling module (DHM) 420,along with a compression rate for each data chunk. DHM 420 performs dataplacement of each data chunk on different storage pools 431-434 based onthe compression rate. In one embodiment, storage pools 431-434 representstorage pools having different RAID protection levels. In anotherembodiment, storage pools 431-434 also represent storage pools havingdifferent performance levels.

In case of corruption or disk failure, the loss of data is magnified bythe compression rate. That is, the higher the compression ratio, thegreater the probability that a small data corruption, like a bit flip,on the storage system corrupts the complete data portion. The higher thecompression rate, the higher are the chances for “rot data” incidents toimpact a larger portion of data and deem the data all corrupted or lost.“Rot data” is an incident where “bit flips” (from 1 to 0 or vice versa)occur spontaneously on the storage and, as such, destroy data integrity.

To protect data from corruption and disk failures, one may establish astorage system with RAID level 5. RAID (redundant array of independentdisks) is a data storage virtualization technology that combinesmultiple disk drive components into a single logical unit for thepurposes of data redundancy or performance improvement. RAID 5 consistsof block-level striping with distributed parity. This is considered anacceptable level of investment for data integrity. Double disk errorsnot protected by RAID 5 result in a huge amount of corrupt or lost data.

RAID technology has grown from a server option to a data protectionrequirement. The first implementations of RAID in 1990 were veryexpensive controller boards with high performance input/output (I/O)processors that were as powerful as the host central processing unit(CPU). At that time, when hardware-based RAID solutions were the onlyoption, the cost of a RAID controller limited the usage to high-pricedservers. Today, RAID is found everywhere—from an operating systemsoftware feature to a stand-alone controller providing advanced dataintegrity in high-end storage area networks. RAID can be found in mobileenvironments such as laptops, as well as desktops, workstations,servers, and external enclosures with a large number of hard diskdrives.

As an example, IBM® General Parallel File System (GPFS™) Native RAID isa software implementation of storage RAID technologies with GPFS. GPFS™Native RAID integrates the functionality of an advanced storagecontroller into the GPFS Network Shared Disk (NSD) server. Unlike anexternal storage controller, where configuration, logical unit (LUN)definition, and maintenance are beyond the control of GPFS, GPFS NativeRAID takes ownership of the disk array to directly match LUN definition,caching, and disk behavior to GPFS requirements. Sophisticated dataplacement and error correction algorithms deliver high levels of storagereliability, availability, serviceability, and performance.

The illustrative embodiments provide a mechanism to enhance therobustness of compressed storage environments. The illustrativeembodiments use dynamic data RAID level definition depending on thecompression rate information for each data chunk. The illustrativeembodiments combine the compression rate information into thesophisticated data placement engine within native RAID softwareimplementations.

Higher RAID protection levels can protect against these errors but theywill require more storage. This runs counter to the purpose ofcompression, which is to reduce the amount of required more storage.

In accordance with the illustrative embodiment, dynamic software definedRAID levels effectively address this contradiction by placing importantdata at a higher RAID level than less important data. The level ofimportance for a particular piece of data is determined from thecompression rate information. The illustrative embodiments combine thereal-time compression engine with the sophisticated data placementengine of software defined RAID.

FIG. 5 is a block diagram of a software defined RAID data handlingmodule in accordance with an illustrative embodiment. Data handlingmodule (DHM) 510 manages the combination of real-time compression engine520, data placement engine 530, and software defined RAID engine 540.DHM 510 captures information from real-time compression engine 520, suchas the amount of compression for each data chunk. DIM 510 mapspredefined thresholds on the compression rate to predefined RAID levels.FIG. 6 shows an example mapping of predefined RAID levels forcompression rates in accordance with an illustrative embodiment. In thedepicted example, chunks with compression rate between 0% and 10% aremapped to RAID 5, chunks with compression rate between 10% and 60% aremapped to RAID 6, chunks with compression rate between 60% and 80% aremapped to RAID 10, and chunks with compression rate between 80% and 100%are mapped to RAID 1. The thresholds and mappings shown in FIG. 6 areexamples to illustrate the aspects of the illustrative embodiments, andother thresholds and mappings may be used within the spirit and scope ofthe illustrative embodiments.

In accordance with one embodiment, the predefined thresholds may be setthrough a configuration option of software defined RAID. DHM 510provides the required RAID levels to software defined RAID engine 540,which creates the RAID configurations in physical storage. Dataplacement engine 530 places chunks into physical storage. Depending onthe increase or decrease of compression rate, data placement engine 530migrates the data into the appropriate RAID levels provided by softwaredefined RAID engine 540 depending on the predefined thresholds withinDHM 510.

In one embodiment, the data center manager may determine that data withhigher compression rate are more important because they are moresusceptible to data corruption, while data with lower compression rateare less susceptible to data corruption and, thus, are less important.Thus, the illustrative embodiments dynamically place important data athigh protection RAID levels with less important data placed at lowerRAID levels. This results in significantly less storage being requiredto obtain the desired protection.

In an alternative embodiment, the data center manager may determine thatdata with higher compression rate are less important because theycontain less information, while data with a lower compression rate aremore important because they contain more information. In the alternativeembodiment, the mechanisms reverse the RAID protection levels, placingdata with higher compression rate on lower RAID protection levels andplacing data with lower compression rate on lower RAID protectionlevels.

Furthermore, in addition to the above, in one embodiment, DHM 510defines performance levels for the different levels of compression rate.Data placement engine 530 automatically migrates data to pre-definedperformance pools. FIG. 7 shows an example mapping of predefinedperformance levels for compression rates in accordance with anillustrative embodiment. In the depicted example, chunks withcompression rates between 0% and 10% are mapped to RAID 5 storage in alow performance storage pool, chunks with compression rates between 10%and 60% are mapped to RAID 6 storage in a medium performance storagepool, chunks with compression rate between 60% and 80% are mapped toRAID 10 storage in a medium performance storage pool, and chunks withcompression rate between 80% and 100% are mapped to RAID 1 storage in ahigh performance storage pool. The thresholds and mappings shown in FIG.7 are examples to illustrate the aspects of the illustrativeembodiments, and other thresholds and mappings may be used within thespirit and scope of the illustrative embodiments.

As shown in FIG. 7, DHM 510 places data with a low compression rate in aslow storage pool, such as near line serial attached SCSI (smallcomputer system interface) (SAS) drives, and data with a highcompression rate in a fast storage pool, such as solid state disk (SSD).

One or more of the above procedures could be present in any giveninstance of software defined RAID.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Java, Smalltalk, C++ or the like,and conventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

FIG. 8 is a flowchart illustrating operation of a data handling modulefor data integrity and acceleration in compressed storage environmentswith software defined native RAID in accordance with an illustrativeembodiment. Operation begins (block 800), and the data handling module(DHM) receives a data portion to write to storage (block 801). The dataportion is divided into a plurality of chunks (block 802). A real-timecompression engine of the DHM performs compression on each data chunk(block 803). The real-time compression engine determines a compressionrate for each de-duplicated chunk (block 804).

A software defined. RAID engine of the DHM then determines a RAID levelfor each chunk based on a value of the compression rate (block 805). Inone embodiment, the DHM maintains a mapping of compression ratethresholds to RAID levels and the software defined RAID engine comparesthe value of the compression rate to the thresholds. For example, if thevalue of the compression rate for a given chunk is less than 10%, thenthe software defined RAID engine assigns RAID level 5 for the givenchunk; if the value of the compression rate for the given chunk isbetween 10% and 60%, then the software defined RAID engine assigns RAIDlevel 6 for the given chunk; if the value of the compression rate isbetween 60% and 80%, then the software defined RAID engine assigns RAIDlevel 10; and, if the value of the compression rate is greater than 80%,then the software defined RAID engine assigns RAID level 1.

Also, in one embodiment, a data placement engine of the DHM determines aperformance level for each chunk based on a value of the compressionrate (block 806). In one embodiment, the DHM maintains a mapping ofcompression rate thresholds to performance levels and the data placementengine compares the value of the compression rate to the thresholds. Forexample, if the value of the compression rate for a given chunk is lessthan 10%, then the data placement engine assigns a low performance levelfor the given chunk and assigns the chunk to a low performance pool ofstorage; if the value of the compression rate for the given chunk isbetween 10% and 80%, then the data placement engine assigns a mediumperformance level for the given chunk; and, if the value of thecompression rate is greater than 80%, then the data placement engineassigns the given chunk to a high performance storage pool.

The DHM then stores each data chunk to storage according to the RAIDlevel and performance level (block 807). The DHM then determines whetherone or more chunks are to be migrated to a different RAID level or adifferent performance pool based on a value of the compression rate(block 808). For example, if the DHM increments a compression rate for agiven chunk in block 804 and the compression rate crosses a threshold,the DHM and the data placement engine migrate the chunk. If one or morechunks are to be migrated, the DHM and data placement engine migrate theone or more chunks with changing RAID protection level and/orperformance level (block 809). Thereafter, or if no data chunks are tobe migrated in block 808, operation ends (block 810).

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

As noted above, it should be appreciated that the illustrativeembodiments may take the form of an entirely hardware embodiment, anentirely software embodiment or an embodiment containing both hardwareand software elements. In one example embodiment, the mechanisms of theillustrative embodiments are implemented in software or program code,which includes but is not limited to firmware, resident software,microcode, etc.

A data processing system suitable for storing and/or executing programcode will include at least one processor coupled directly or indirectlyto memory elements through a system bus. The memory elements can includelocal memory employed during actual execution of the program code, bulkstorage, and cache memories which provide temporary storage of at leastsome program code in order to reduce the number of times code must beretrieved from bulk storage during execution.

Input/output or I/O devices (including but not limited to keyboards,displays, pointing devices, etc.) can be coupled to the system eitherdirectly or through intervening I/O controllers. Network adapters mayalso be coupled to the system to enable the data processing system tobecome coupled to other data processing systems or remote printers orstorage devices through intervening private or public networks. Modems,cable modems and Ethernet cards are just a few of the currentlyavailable types of network adapters.

The description of the present invention has been presented for purposesof illustration and description, and is not intended to be exhaustive orlimited to the invention in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the artwithout departing from the scope and spirit of the describedembodiments. The embodiment was chosen and described in order to bestexplain the principles of the invention, the practical application, andto enable others of ordinary skill in the art to understand theinvention for various embodiments with various modifications as aresuited to the particular use contemplated. The terminology used hereinwas chosen to best explain the principles of the embodiments, thepractical application or technical improvement over technologies foundin the marketplace, or to enable others of ordinary skill in the art tounderstand the embodiments disclosed herein.

What is claimed is:
 1. A method, in a data processing system, for dataintegrity and acceleration in compressed storage environments incombination with software defined native redundant array of independentdisks (RAID), the method comprising: receiving a data portion to writeto storage; dividing the data portion into a plurality of chunks;performing, by a real-time compression engine, real-time compression ona given chunk within the plurality of chunks to form a compressed chunk;receiving, by a data handling module, the compressed chunk and acompression rate for the given chunk from the real-time compressionengine; determining, by the data handling module, a RAID level for thegiven chunk based on a value of the compression rate; and storing, bythe data handling module, the compressed chunk based on the determinedRAID level.
 2. The method of claim 1, wherein determining the RAID levelfor the given chunk comprises comparing the value of the compressionrate to at least one threshold, wherein the at least one threshold aremapped to corresponding RAID levels.
 3. The method of claim 2, whereinvalues of the compression rate less than a first threshold are mapped toRAID 5, wherein values of the compression rate greater than the firstthreshold and less than a second threshold are mapped to RAID 6, whereinvalues of the compression rate greater than the second threshold andless than a third threshold are mapped to RAID 10, and wherein values ofthe compression rate greater than the third threshold are mapped toRAID
 1. 4. The method of claim 2, wherein storing the given chunkcomprises migrating the given chunk from a previous storage pool to anew storage pool responsive to the value of the compression ratecrossing a threshold within the at least one threshold.
 5. The method ofclaim 1, further comprising determining a performance level for thegiven chunk based on the value of the compression rate, wherein storingthe given chunk comprises storing the given chunk based on thedetermined RAID level and the determined performance level.
 6. Themethod of claim 5, wherein determining the performance level for thegiven chunk comprises comparing the value of the compression rate to atleast one threshold, wherein the at least one threshold are mapped tocorresponding RAID levels.
 7. The method of claim 6, wherein values ofthe compression rate less than a first threshold are mapped to a lowperformance pool of storage, wherein values of the compression rategreater than the first threshold and less than a second threshold aremapped to a medium performance pool of storage, and wherein values ofthe compression rate greater than the second threshold are mapped to ahigh performance pool of storage.
 8. A computer program productcomprising a computer readable storage medium having a computer readableprogram stored therein, wherein the computer readable program, whenexecuted on a computing device, causes the computing device to: receivea data portion to write to storage; divide the data portion into aplurality of chunks; perform, by a real-time compression engine,real-time compression on a given chunk within the plurality of chunks;receive, by a data handling module, the compressed chunk and acompression rate for the given chunk from the real-time compressionengine; determine, by the data handling module, a RAID level for thegiven chunk based on a value of the compression rate; and store thegiven chunk based on the determined RAID level.
 9. The computer programproduct of claim 8, wherein determining the RAID level for the givenchunk comprises comparing the value of the compression rate to at leastone threshold, wherein the at least one threshold are mapped tocorresponding RAID levels.
 10. The computer program product of claim 9,wherein values of the compression rate less than a first threshold aremapped to RAID 5, wherein values of the compression rate greater thanthe first threshold and less than a second threshold are mapped to RAID6, wherein values of the compression rate greater than the secondthreshold and less than a third threshold are mapped to RAID 10, andwherein values of the compression rate greater than the third thresholdare mapped to RAID
 1. 11. The computer program product of claim 9,wherein storing the given chunk comprises migrating the given chunk froma previous storage pool to a new storage pool responsive to the value ofthe compression rate crossing a threshold within the at least onethreshold.
 12. The computer program product of claim 8, furthercomprising determining a performance level for the given chunk based onthe value of the compression rate, wherein storing the given chunkcomprises storing the given chunk based on the determined RAID level andthe determined performance level.
 13. The computer program product ofclaim 12, wherein determining the performance level for the given chunkcomprises comparing the value of the compression rate to at least onethreshold, wherein the at least one threshold are mapped tocorresponding RAID levels.
 14. The computer program product of claim 13,wherein values of the compression rate less than a first threshold aremapped to a low performance pool of storage, wherein values of thecompression rate greater than the first threshold and less than a secondthreshold are mapped to a medium performance pool of storage, andwherein values of the compression rate greater than the second thresholdare mapped to a high performance pool of storage.
 15. An apparatuscomprising: a processor; and a memory coupled to the processor, whereinthe memory comprises instructions which, when executed by the processor,cause the processor to: receive a data portion to write to storage;divide the data portion into a plurality of chunks; perform, by areal-time compression engine, real-time compression on a given chunkwithin the plurality of chunks; receive, by a data handling module, thecompressed chunk and a compression rate for the given chunk from thereal-time compression engine; determine, by the data handling module, aRAID level for the given chunk based on a value of the compression rate;and store, by the data handling module, the given chunk based on thedetermined RAID level.
 16. The apparatus of claim 15, whereindetermining the RAID level for the given chunk comprises comparing thevalue of the compression rate to at least one threshold, wherein the atleast one threshold are mapped to corresponding RAID levels.
 17. Theapparatus of claim 16, wherein values of the compression rate less thana first threshold are mapped to RAID 5, wherein values of thecompression rate greater than the first threshold and less than a secondthreshold are mapped to RAID 6, wherein values of the compression rategreater than the second threshold and less than a third threshold aremapped to RAID 10, and wherein values of the compression rate greaterthan the third threshold are mapped to RAID
 1. 18. The apparatus ofclaim 15, further comprising determining a performance level for thegiven chunk based on the value of the compression rate, wherein storingthe given chunk comprises storing the given chunk based on thedetermined RAID level and the determined performance level.
 19. Theapparatus of claim 18, wherein determining the performance level for thegiven chunk comprises comparing the value of the compression rate to atleast one threshold, wherein the at least one threshold are mapped tocorresponding RAID levels.
 20. The apparatus of claim 19, wherein valuesof the compression rate less than a first threshold are mapped to a lowperformance pool of storage, wherein values of the compression rategreater than the first threshold and less than a second threshold aremapped to a medium performance pool of storage, and wherein values ofthe compression rate greater than the second threshold are mapped to ahigh performance pool of storage.